Sustaining groundwater data, lessening vulnerability

The challenge

Groundwater has been the only source of water supply for District customers. The Santa Cruz Mid-County Basin has been in a serious state of overdraft. Cumulative effects of pumping the aquifer have exceeded the amount annually replenished by rainfall. Multi-year drought conditions compounded the situation.

A community water plan to achieve sustainability had been developed since saltwater contamination was first detected within the expansive monitoring well network in the 1980’s.

After state law to regulate aquifers passed in 2014, existing collaboration with adjacent water agencies was formalized. Collectively members are addressing sustainability of shared resources, creating a long-term plan accounting
for sea level rise, a drier climate, and an increasing population that will increase freshwater demand over the next several decades.

Key Technical Specifications:

• Centralize storage of diverse and large datasets (wells, weather, water quality, SCADA, etc.) in data silos
• Ease access & visualization to relevant datasets by authorized users
• Automate data processing to improve data quality & reduce staff time to do simple data management tasks
• Customize data exports for SGMA / regulatory reporting

The solution

The utility implemented Water Information System by KISTERS (WISKI) as its centralized data system to secure data and overcome differences in file formats from historical and current sensors and loggers.

Personnel have been empowered to more easily evaluate the state of the groundwater basin as the Sustainable Groundwater Management Act (SGMA) was signed into law in 2014.

Enhanced quality control processes and data visualization tools affirm that manual water level measurements and automated logger data values fall within an acceptable range of error. Water level data across multiple wells are quickly plotted and explored with analytical tools. Previously, staff received an annual report with static plots for review.

Ahead of future state regulations regarding groundwater quality, Soquel Creek Water District is integrating water quality and quantity datasets.

The benefits

Today Soquel Creek Water District is better informing itself and its customers. More efficient data management helps communicate water conservation success; less pumping from production wells supports aquifer recovery. While population and demand are expected to increase, the water utility continues to evaluate strategies for sustainability.

By integrating time series and spatial data, staff identify that pumping less from specific wells allows groundwater levels to recover. Water conservation by customers also supported a 25% reduction in pumping. Integrating data from SCADA systems, weather stations, and in-situ sensors also confirms that deep well pumping has no impact on shallow wells. Rain however raises water levels in shallow & medium wells.

The organization’s increase in analytical capacity & technical capabilities to share quality-controlled datasets with consultants now streamlines time and costs for developing annual reports. Datasets are shared with an approved hydrogeologist consultant as needed. Instead of tedious data validation, this contractor can continue to develop and calibrate the basin’s integrated surface and groundwater model, which had begun while other groundwater sustainability agencies (GSA) were still forming.

To increase the reliability of the District’s water supply & mitigate risk of further saltwater contamination, an advanced water purification facility has been designed to recycle treated wastewater and purify it to drinking water standards. Purified water would replenish the basin and create a seawater intrusion barrier. A $50M California State Prop 1 grant will cover 50% projected construction costs for a new groundwater replenishment facility & distribution system. Federal grants have also been awarded to apply toward construction and lessen the vulnerability of the drinking water supply.

Soquel Creek Water District continues to promote deeper understanding of the aquifer system among staff, consultants, and the public.